Abstract
The effects of microstructure on the oxygen permeation in SrCo0.8Fe0.2O3-delta (SCFO) and La0.2Sr0.8Fe0.8Cr0.2O3 (LSFCO) was investigated using disc samples fabricated under different processing conditions. The microstructure of LSFCO remained unchanged when the sintering temperature was increased from 1300 to 1450 degrees C, but the average grain size of SCFO increased considerably when the sintering temperature was increased from 930 to 1200 degrees C. The change in grain size was found to have a strong effect on the oxygen permeation flux in SCFO, which increased considerably as the grain size was decreased. This indicates that the contribution of the grain boundary diffusion to the steady state oxygen flux in SCFO is substantial and grain boundaries provide faster diffusion paths in oxygen permeation through the samples.